GENETIC ANALYSIS OF MEIOTIC CENTROMERE FUNCTION

描述：该提案的具体目标是从基因上识别 并描述着丝粒组装和功能所需的基因 在减数分裂中。 这些研究将在雄性果蝇中进行 黑腹果蝇，一种模式遗传生物，其着丝粒在功能上出现 在结构上与人类的着丝粒相似 突变体已经被诱导 使用转座子诱变，并筛选其对 减数分裂不稳定的双着丝粒染色体（染色体）的传递 有两个着丝粒）。 增加或优先选择的突变 选择该染色体的减数分裂传递减少。 这些将 在遗传学和细胞学上进行表征以鉴定候选基因 用于着丝粒结构和/或调节蛋白。 另外还有按 一组携带缺陷的染色体， 的常染色体常染色质将被测试在反式的影响， 这条双着丝粒染色体的分离。 该缺陷屏幕将 确定基因组中含有对基因组重要的基因的区域， 双着丝粒的稳定性。 选定的突变体将通过遗传和 分子方法，并通过基于转座子的方法或 染色体游走 克隆的cDNA将在细菌中表达， 杆状病毒产生的抗原用于生产多克隆抗体。 此外，双着丝粒染色体的性质将进一步研究 遗传的 双着丝粒的两个着丝粒将分离， 在单独的染色体上回收，以允许测试每个染色体的特性， 着丝粒单独。 新的双着丝粒染色体将产生， 原始双着丝粒的衍生物。 这些将被描述为 从遗传学和细胞学的角度来确定影响 双着丝粒染色体的着丝粒的有丝分裂和减数分裂行为。

DESCRIPTION: The specific aims of this proposal are to genetically identify and characterize genes required for the assembly and function of centromeres in meiosis. These studies will be carried out in male Drosophila melanogaster, a model genetic organism whose centromeres appear functionally and structurally similar to human centromeres. Mutants have been induced using transposon mutagenesis, and were screened for their effects on the transmission of a meiotically unstable dicentric chromosome (a chromosome with two centromeres). Mutations that either increased or preferentially decreased meiotic transmission of this chromosome were selected. These will be characterized genetically and cytologically to identify candidate genes for centromere structural and/or regulatory proteins. In addition, a collection of deficiency-bearing chromosomes that together delete 80 percent of the autosomal euchromatin will be tested in trans for effects on the segregation of this dicentric chromosome. This deficiency screen will identify regions of the genome that contain genes important for the stability of the dicentric. Selected mutants will mapped by genetic and molecular methods, and cloned either by transposon-based methods or by chromosomal waLking. Cloned cDNAs will be expressed in bacteria or baculovirus to produce antigen for the production of polyclonal antibodies. Additionally, the nature of the dicentric chromosome will be further studied genetically. The two centromeres of the dicentric will be detached and recovered on separate chromosomes to allow tests of the properties of each centromere individually. New dicentric chromosomes will be generated as derivatives of the original dicentric. These will be characterized genetically and cytologically to identify properties that influence the mitotic and meiotic behavior of centromeres of dicentric chromosomes.